Design and development of a hybrid eVTOL UAV with guided parachute delivery for urban logistics

In recent years, we have seen various urban parcel delivery solutions designed to overcome the limitations of ground transportation and meet the surge in delivery demand. Many of the proposed systems are in the form of conventional unmanned aerial vehicles (UAVs). Multirotor UAVs typically suffer from limited endurance and range, whereas fixed-wing platforms require runways and lack hovering capability, restricting their applicability in dense urban environments. This paper presents the design and development of a hybrid electric vertical take-off and landing (eVTOL) UAV with a 3.6-m wingspan, combining vertical take-off and landing capability with efficient fixed-wing cruise performance. To eliminate time-consuming landing operations and enhance point-delivery precision, the proposed system integrates a dual parachute-assisted payload deployment mechanism, enabling the delivery of two independent packages without landing. An integrated design framework is adopted, combining aerodynamic modeling, mechanical design, hybrid composite-additive manufacturing, and flight control algorithms. The aerodynamic characteristics of the aircraft are obtained through a unified database generated using the Vortex Lattice Method (VLM), Computational Fluid Dynamics (CFD), and nonlinear simulation environments. Based on this model, trim analysis and stability characteristics are derived and utilized in the controller design. A hierarchical control architecture incorporating Model Predictive Control (MPC), Linear Quadratic Regulator (LQR), and Proportional–Integral–Derivative (PID) controllers is implemented to manage hover, transition, and forward-flight. The proposed system is evaluated through nonlinear simulations conducted in Gazebo and ROS, as well as indoor experimental stability tests. Simulation results demonstrate stable transition behavior, with hover-to-cruise transition completed in 15 s and a maximum altitude deviation of ± 3 m. Trajectory tracking performance across multiple flight modes yielded a root mean square error (RMSE) of 0.5–1.5 m. The guided parachute delivery system is validated through dedicated simulations, achieving a Circular Error Probable (CEP) of about 1 m for each independent package under nominal wind conditions of up to 7 m/s. The aircraft is designed to carry a total payload of 8 kg with a demonstrated cruise efficiency of 15 Wh/km and an operational range of 16 km, while maintaining low manufacturing and operational costs under nominal conditions; performance under adverse wind scenarios is reserved for future experimental validation. The results indicate that the proposed hybrid VTOL UAV offers a viable and scalable solution for multi-package urban delivery applications, combining aerodynamic efficiency, control robustness, and manufacturing flexibility.